i2c: at91: add new driver

This driver has the following properties compared to the old driver:
1. Support for multiple interfaces.
2. Interrupt driven I/O as opposed to polling/busy waiting.
3. Support for _one_ repeated start (Sr) condition, which is enough
   for most real-world applications including all SMBus transfer types.
   (The hardware does not support issuing arbitrary Sr conditions on the
    bus.)

testing: SoC: at91sam9g45
	 - BQ20Z80 battery SMBus client.
	 - on a 2.6.38 kernel with several i2c clients (temp-sensor,
	   audio-codec, touchscreen-controller, w1-bridge, io-expanders)

Signed-off-by: Nikolaus Voss <n.voss@weinmann.de>
Reviewed-by: Felipe Balbi <balbi@ti.com>
Tested-by: Hubert Feurstein <h.feurstein@gmail.com>
Tested-by: Ludovic Desroches <ludovic.desroches@atmel.com>
Reviewed-by: Nicolas Ferre <nicolas.ferre@atmel.com>

[wsa: squashed with the following patches from Ludovic to have some flaws
fixed:
        i2c: at91: use managed resources
        i2c: at91: add warning about transmission issues for some devices
        i2c: at91: use an id table for SoC dependent parameters
]

Signed-off-by: Ludovic Desroches <ludovic.desroches@atmel.com>
Signed-off-by: Wolfram Sang <w.sang@pengutronix.de>
This commit is contained in:
Nikolaus Voss
2011-11-08 11:49:46 +01:00
committed by Wolfram Sang
parent a879e9c34b
commit fac368a040
15 changed files with 545 additions and 22 deletions

View File

@ -237,8 +237,8 @@ static struct clk_lookup periph_clocks_lookups[] = {
CLKDEV_CON_DEV_ID("spi_clk", "atmel_spi.1", &spi1_clk),
CLKDEV_CON_DEV_ID("t0_clk", "atmel_tcb.0", &tcb0_clk),
CLKDEV_CON_DEV_ID("t0_clk", "atmel_tcb.1", &tcb0_clk),
CLKDEV_CON_DEV_ID(NULL, "at91_i2c.0", &twi0_clk),
CLKDEV_CON_DEV_ID(NULL, "at91_i2c.1", &twi1_clk),
CLKDEV_CON_DEV_ID(NULL, "i2c-at91sam9g10.0", &twi0_clk),
CLKDEV_CON_DEV_ID(NULL, "i2c-at91sam9g10.1", &twi1_clk),
CLKDEV_CON_DEV_ID("pclk", "ssc.0", &ssc0_clk),
CLKDEV_CON_DEV_ID("pclk", "ssc.1", &ssc1_clk),
CLKDEV_CON_DEV_ID(NULL, "atmel-trng", &trng_clk),